One example of a chemical change is the rusting of iron. An additional example is the digestion of food by the body. A chemical change is an irreversible change that involves reactants and the creation of new products.
The rusting of iron is an example of a type of chemical change called an oxidation reaction, which results from contact with oxygen. Digestion of food is possible with the use of enzymes in the body, which break down food into simpler components that can be utilized by the body. The enzyme amylase, for example, is present in the saliva and begins to break down sugars as soon as they enter the mouth.